Distributed control systems are often used in a number of commercial, industrial and home applications, in particular to monitor and control operations at manufacturing, chemical processing and similar industrial operations, to monitor and control environmental and other factors and so forth. In a manufacturing operation, a distributed control system will typically control machines which facilitate the manufacture and assembly of the products being manufactured. In addition, in a chemical processing operation, a distributed control system may control valves to control rates of flow of chemicals into and out of reaction chambers, reaction temperatures and pressures and the like which are required to carry out the chemical process. In addition, to controlling the manufacturing or chemical process, distributed control systems may perform bookkeeping operations to keep track of the inventory of inputs required for the manufacturing or chemical process, as well as the inventory of outputs produced by the operation.
Typical distributed control systems essentially comprise large, centrally-located and expensive computer systems. A number of problems arise out of use of such computer systems, including the facts that they are expensive to maintain and typically have limited expansion capabilities.